The creation of computer generated 3D content is becoming popular. Computer generated 3D content typically includes one or more animation controls. A 3D model of an object can be specified using a mesh of vertices and polygons that define the shape of the object in 3D. The 3D model can also have a texture applied to the mesh that defines the appearance of the mesh. 3D models used for animation can also include a rig that defines the articulated portions of the mesh and/or define the deformation of the mesh of the model as a function of the motion of the rig. The process of defining the rig is often referred to as rigging a 3D model. The animation of a rigged 3D model involves applying motion data to the model's rig to drive the model's mesh. The generation of animation can be technically challenging and is often performed by artists with specialized training.